Electronic control system for a vacuum system

ABSTRACT

A programmable control unit for a vacuum cleaning system, such as central vacuum cleaning system. A control unit is programmed after manufacture to execute a particular control program for performing various diagnostic and operational functions including user interface, voltage level detecting, voltage monitoring, current monitoring, user interface, power supply control, temperature monitoring, AC line frequency detection, operation data recording, speed control program selection, expansion bus interface and service tool interface. Power control to the vacuum motor is facilitated by the control unit directly through a triode for alternating current (TRIAC). Manufacturing costs are reduced by producing a single programmable control unit that can be programmed with a control program corresponding to a variety of different vacuum cleaning devices across a manufacturer&#39;s product line.

FIELD OF THE INVENTION

The present invention relates to vacuum cleaner systems and more particularly to a control system for central vacuum cleaner systems and other vacuum devices.

BACKGROUND OF THE INVENTION

Electric vacuum cleaning systems have become ubiquitous as the preferred method of cleaning carpeted and hard floors. These devices are manufactured in a variety of configurations including canister, upright, power wands, power heads, handhelds, etc. These different vacuum types differ in many design features such nozzle size and configuration, power agitation, cyclonic airflow and advanced dust filtering, however, they all share fundamental components. Vacuum cleaners typically include a handle portion attached to a cleaning nozzle/attachment, a dirt reservoir and a vacuum motor—that is, a motor and fan assembly that generates a working airflow from the nozzle to the dirt reservoir. Depending on the configuration all these items may be integrated into an upright or wand unit or the motor and reservoir may be a separate unit tethered to the cleaning attachment via a flexible vacuum hose.

Due in part to the inconvenience of pushing an entire vacuum and also the power, weight and size limitations of the above types of vacuums, central vacuum systems were developed. Central vacuum systems use a central power unit with a relatively high power vacuum motor and large dirt reservoir. Such central vacuums are typically located outside of the main living area of a home, such as, for example, in a garage, basement, attic, etc. A network of conduits hidden below floorboards, above ceilings and between walls connects wall based vacuum outlets to the central power unit. The power unit is usually connected to a dedicated 15 amp or larger power circuit and may run on 240 and 120 volt alternating current power (AC), but power requirements may vary depending on the characteristics of the local power system. By isolating the powerful vacuum motor outside of the primary living area, the homeowner is able to enjoy strong suction power not typically available in conventional integrated vacuum cleaning devices without having to hear the noise that such a high power vacuum motor generates and without having to physically manipulate such a unit. Typically, central vacuum systems are equipped with one or more hose/cleaning attachment modules that connect to wall connectors located throughout the house. In addition to providing an airflow path from the cleaning attachment to the dirt canister, these wall connectors may also provide a power connection to operate active components of the cleaning attachments and to permit the user to turn the vacuum unit on or off. U.S. Pat. No. 5,400,463 illustrates an example of a central vacuum system. This patent is hereby incorporated by reference into the disclosure of this application in its entirety.

Though central vacuum systems differ from integrated vacuum systems in that they are typically more robust and are built into the house, their basic design has many similarities with conventional integrated vacuums and therefore, like problems are often addressed in improving their design. As consumer vacuum cleaning devices have become more complicated, so too have the electronic control systems required to facilitate advanced features. The trend has been to migrate toward microcomputer-based control. U.S. Pat. Nos. 5,542,146 and 4,654,924 both describe microcomputer-based control systems for vacuum cleaners and are hereby incorporated by reference in their entirety.

Another innovation in vacuum cleaner control system design is the interchangeable control panel. U.S. Pat. No. 6,360,399 describes an interchangeable control panel that is removably attached to the housing of a hand-held vacuum cleaner. The interchangeable control panel can be configured to provide the feature mix of a given product model without requiring redesign of the housing of the power unit to accommodate the features mixes of the different product models. While this solution does have the potential to reduce manufacturing costs by allowing multiple products to utilize a common housing, it still suffers from some significant drawbacks. For example, in this system a unique control interface must be designed for each product. The control interface, typically a electronic module with one or more circuit boards, processors and other electrical circuit components, is typically the most expensive part of the vacuum to design and manufacture. Having to design and manufacture a separate one for each product across a product line only reduces the costs of an inexpensive component—the housing—and actually limits the configurations and features that can be installed because they must be compatible with the physical dimensions of the housing. The housing, which is typically made of plastic and/or metal, is relatively inexpensive to design and manufacture because it is merely a passive “container” to hold the operating parts, such as the vacuum motor, transformer, filter and control system. Thus, the interchangeable control system described in this patent system is expected not to appreciably reduce costs.

Despite the advent of these computer-based vacuum cleaner controllers, control systems still suffer from being overly expensive, complicated and difficult to design. Providing robust, flexible, scalable control systems remains a technical obstacle for vacuum cleaning systems—both central vacuums and integrated vacuum cleaners. Other problems and drawback exist with known systems.

SUMMARY OF THE INVENTION

According to a first aspect, the present invention provides a vacuum cleaner system. The vacuum cleaner system according to this aspect comprises a line power input, a dirt collection unit, at least one dirty air intake conduit defining an airflow path to the vacuum unit and terminating in a dirt collection unit, a vacuum motor adapted to generate a working airflow from the dirty air intake to conduit to the dirt collection unit, and a programmable control unit having a power conditioning module and adapted to be programmed with one or more of a plurality of different control programs that control the power conditioning module to provide power from the line power input to drive the vacuum motor

Another exemplary embodiment according to this invention provides a product line of distinct central vacuums. Each central vacuum in the product line of distinct central vacuums according to this embodiment comprises an integral power unit, comprising a line power input, a dirty air intake, a dirt reservoir, a particulate barrier, an air outlet, a vacuum motor configured on a side of the particulate barrier fluidly opposite the dirt reservoir and adapted to generate a working airflow from the dirty air intake to the particulate barrier, and expect the working airflow out of the air outlet, and a programmable control unit, including a power conditioning unit adapted to condition a line power, wherein the programmable control unit is programmed with a control program specific to one of the distinct central vacuums for controlling the power conditioning unit, wherein the control program comprises a feature set including a maximum power watt output level for the vacuum motor.

An additional exemplary embodiment according to this invention provides a vacuum cleaner system. The vacuum cleaner system according to this embodiment comprises a line power input, an air intake, a dirt collection reservoir, a vacuum motor adapted to generate a working airflow from the dirty air intake to conduit to the dirt collection unit, and a programmable control unit including a power conditioning module and adapted to be programmed with one or more of a plurality of different control programs, wherein each control program corresponds to a different product in a vacuum manufacturer's product line and specifies a maximum current level for the power conditioning module to deliver to the vacuum motor thereby providing each different product in the product line with at least one different operational characteristic.

These and other embodiments and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a residential structure containing a central vacuum system usable with the various embodiments of the invention and illustrating the various central vacuum system components.

FIG. 2 is a plan view of an exemplary central vacuum power unit of a central vacuum system according to the various embodiments of the invention.

FIG. 3 is a cut away plan view of the exemplary central vacuum power unit illustrated in FIG. 2 illustrating according to the various embodiments of the invention.

FIG. 4 is a block diagram of an exemplary digital microprocessor-based control unit for a vacuum cleaning system illustrating control unit modules according to various embodiments of the invention.

FIG. 5 is an exemplary circuit diagram illustrating a circuit topology for the vacuum cleaning system control unit according to at least one embodiment of the invention.

DETAILED DESCRIPTION

The following description is intended to convey a thorough understanding of the described exemplary embodiments by providing a number of specific embodiments and details involving a control unit for central vacuum cleaning systems. It should be appreciated, however, that the present invention is not limited to these specific embodiments and details, which are exemplary only. It is further understood that one possessing ordinary skill in the art, in light of known systems and methods, will appreciate the use of the invention for its intended purposes and benefits in any number of alternative embodiments, depending upon specific design and other needs.

Referring now to FIG. 1, a schematic diagram of a residential structure employing a central vacuum cleaner system is illustrated. The residential structure 10 is a multilevel structure with a primary residential portion 10A and secondary portion 10B. The central vacuum cleaner of FIG. 1 comprises a power unit 100 located in the second portion 10B, an air intake pipe 120 connected to an air intake manifold 122 that is connected to a network of vacuum piping 125 terminating in a plurality of individual wall connectors 130. In the example of FIG. 1, the vacuum piping is concealed between the walls of the residential structure 10. In practical application, the vacuum piping may run under floor boards, through an attic, over a ceiling, etc., in a manner analogous to plumbing and electrical lines.

In the example of FIG. 1, cleaning nozzles 200 are shown connected to the wall connectors 130 via flexible vacuum hoses 210. In this way, the operator is only required to move the cleaning nozzle 200 and hose 210 from room to room rather than transporting the entire vacuum system to different locations in the structure 10.

In some systems, the wall connector 130 may have a switch to turn on the vacuum motor 170 (FIG. 3) located in the power unit 100. Alternatively, the switch may be located on the nozzle 200 or other power switching devices, such as acoustic, radio or infrared may be used. In these systems, the wall unit connector may supply a low voltage connection to power the switch. In most systems, any powered elements included in the nozzle, such as brushers, agitators, etc., are powered by a separate connection to a regular wall power outlet. Alternatively, the wall connector 130 may also supply power for any powered elements of the nozzle as well as provide a control signal bus for sending control and/or status signals between the wall connector 130 and the remote power unit 100. By isolating the power unit 100 in second portion 10B of the residential structure 10, a relatively large, heavy and loud vacuum motor may be employed providing suction power that greatly exceeds that of conventional integrated vacuum systems.

Referring now to FIG. 2, a plan view of an exemplary central vacuum power unit 100 of a central vacuum system according to various embodiments of the invention is illustrated. In the example of FIG. 2, the power unit 100 has a generally cylindrical shape. This shape is exemplary only. The power unit 100 may take the form of a variety of different shapes.

During operation of the vacuum system, dirty air is drawn through the air intake pipe 120 in the direction indicated by the arrow labeled “IN” into the dirt collection chamber 115. The dirt collection chamber 115 is removably attached to the main body portion 110 of the power unit 100 via one or more mechanical fasteners 117. An interface 160 is mounted on a surface of the main body portion 110. The interface 160 may comprise one or more LEDs or other status indicator lights and/or a small display screen and/or user control buttons. The cleaned vacuum air exits the power unit 100 through an air exit vent 180 in the direction indicated by the arrow labeled “OUT.” Electrical power is supplied through conventional plug or hardwire connection via a power cord 140. Also, a power/control cable 142 may run from the power unit 100 along the path defined by the vacuum conduits 125 to supply the power and/or control interface connection at each wall connector 130. The power unit 100 may be free standing, wall mounted, or otherwise attached to the residential structure 10.

Referring now to FIG. 3, a cut away plan view of the exemplary central vacuum power unit 100 shown in FIG. 2 according to various embodiments of the invention is depicted. The exemplary power unit 100 depicted in FIG. 3 includes an air input chamber 119 which receives dirty air input from air intake 120. Solids and other relatively massive debris fall below the input chamber 119 to the bottom of the dirt collection chamber 115. An air filter 150 is mounted between the input chamber 119 and the vacuum motor 170 (which may comprise any combination of a fan and motor adapted to generate a working airflow) to trap smaller, particulate matter picked up by the vacuum system and to prevent this matter from entering the vacuum motor 170 or from being expelled out of the air output tube 180. The shown configuration may be altered in any way to provide other dirt collection arrangements, as will be understood by those of ordinary skill in the art. For example, the dirt collection chamber 115 may instead comprise a bag filter, or one or more features may be added to provide a cyclonic air separation system.

A control unit 300 provides electrical control signals and conditioned power to the vacuum motor 170 as well as to the power/data bus cable 142. Preferably, the control unit 300 is based on one or more printed circuit boards (PCBs). In a preferred embodiment, the control unit 300 comprises a single printed circuit board. Also, in a preferred embodiment, the control unit 300 replaces the necessity of a separate power transformer by including a triode for alternating current (TRIAC) that can be used to control the amount of current that flows to the vacuum motor 170. In this way, the incoming wall power may be directly controlled by the microprocessor-based control unit 300 via the TRIAC. It should be appreciated that in other embodiments, a separate power supply and/ or transformer may be used to condition the line power for use by the vacuum motor 170. As used herein, the term “power conditioning module” will be used to refer generally to a feature of the control unit enabling it to control power to the vacuum motor 170. As noted above, in a preferred embodiment, this is done directly through a TRIAC. However, in other embodiments, this may be done through a control unit 300 interface to a power supply, transformer or other conventional power conditioning device.

The power conditioning module of the control unit 300 receives an incoming power supply from the power cord 140 and conditions the incoming power supply to an output power supply that drives the vacuum motor 170. This may comprise delivering a particular current and/or voltage level to the vacuum motor 170, or changing the power, such as, from alternating current (AC) to direct current (DC) if so required by the vacuum motor 170. In a preferred embodiment, the vacuum motor 170 is an AC motor, however, in various other embodiments, the vacuum motor may be a DC vacuum motor, that is, run on DC power. The power conditioning module of the control unit 300 may alternatively condition battery power, or other AC or DC power, into the necessary output power supply for the vacuum motor 170. Though not depicted in the figure, the control unit 300 may also be in electrical communication with a human interface on an outside surface of the power unit 100, such as interface 160 depicted in FIG. 2.

During operation, when a user activates the vacuum system at the nozzle 200 or wall connector 130, the control unit 300 causes the power conditioning module to deliver power to the vacuum motor 170, thereby generating a suction force running from the nozzle 200 to the air input chamber 119, through the filter 150, past the vacuum motor 170 and out the air exit 180. Debris, dust and other particulate matter are trapped in the filter 150 or in the dirt collection chamber 115.

As noted herein, the vacuum motor 170 may comprise any known vacuum motor, that is, an electric motor fan combination that generates a working airflow. As discussed above, in a preferred embodiment, the vacuum motor is an AC motor whose current is supplied by a TRIAC. However, the various embodiments of the invention may also be used with a DC motor. Vacuum motors are usually rated based on the maximum number of air watts they deliver. An air watt is a mathematical measurement of vacuum pressure and airflow. Air watt ratings provide a useful cleaning performance value of a vacuum because they specify the relationship of lifting ability and dirt moving ability.

While the air exit 180 may simply be an air conduit exiting into the ambient air space, in at least one embodiment, the air output may comprise sound damping apparatus 175 in the power unit 100, such as that disclosed in U.S. Pat. No. 5,737,797 which is incorporated by reference in its entirety into the disclosure of this application. In at least one embodiment, the air output may also comprise a muffler device such as that disclosed in U.S. Pat. No. 6,052,863, which is also incorporated by reference in its entirety into the disclosure of this application.

In various embodiments, the control unit 300 is a unitary structure, that is, a single, microprocessor-based board. In a preferred embodiment, the control unit 300 is implemented as an embedded microprocessor running a programmable, firmware-based control program for facilitating control, maintenance, service and other functions, as illustrated in FIG. 5. By consolidating vacuum control features into a single programmable board, greater flexibility, lower costs, and enhanced functionality may be achieved. For example, in at least one embodiment, the control unit 300 can be programmed after manufacture, either before or after power unit assembly to operate according to a particular operating program. This allows a single control unit 300 to be manufactured for vacuum systems across an entire product line and even to utilize a single motor that is intentionally run at a lower power level to reserve available power for other devices, reduce power consumption (either always or intermittently) or to sell the motor in a device marketed at a price point below higher-end models. Because of this feature, a single control unit may be used in a variety of different vacuum cleaners having differing motor sizes and feature set, or a single motor can be used across a product line of vacuum cleaners operating at different power levels and different input power characteristics. This can reduce manufacturing costs to vacuum manufacturers due to the reduction in the number of different PCB's that need to be made and the reduction in the number of motors necessary to developing a comprehensive product line.

The present invention also preferably reduces and/or eliminates the traditional reliance on multiple daughter boards that have been installed on vacuum cleaners to provide various additional features. For example, in prior devices, one board may have been used to control the power supply, another for monitoring motor performance, another for interfacing with a repair tool, etc. By developing a single, robust, microprocessor-based platform, firmware can be developed to allow the processor to perform many or all control operations. Furthermore, the use of a single platform allows simple changes and upgrades to the entire system or to specific system features after board manufacture.

In a preferred embodiment, the control unit 300 senses a voltage level (i.e., 220V or 115V) supplied by the power cord 140 to the power conditioning module. Based on the detected value, the control unit 300 causes the power conditioning module to convert the power to a predetermined level to deliver to the vacuum motor 170. For example, in at least one embodiment, the control unit 300 determines the voltage level by measuring the voltage across a flyback transformer (not shown) that is used to supply the low power for the active electronics in the control unit 300 circuit while the secondary of the transformer is de-energized.

As is discussed in greater detail below in the context of FIG. 4, by utilizing the single board, microprocessor based control unit according to the various embodiments of the invention, firmware may be installed that allow the unit to perform many different functions including voltage monitoring, current monitoring, soft motor starts, recording of historical performance data, speed control, human interface, motor lock protection, error reset, harmonic current emissions reduction, high voltage shut off, operation timeout and AC line frequency detection.

Referring now to FIG. 4, a block diagram of an exemplary single PCB, microprocessor-based control unit for a vacuum cleaning system according to various embodiments of the invention is illustrated. The control unit 300 comprises a plurality of different modules which, in various embodiments, provide functionality that enable the unit 300 to perform a variety of different control functions for a vacuum cleaning system, such as, for example, a central vacuum system, a truck based vacuum system, a conventional integrated portable vacuum or other vacuum system.

In the example of FIG. 4, there are several modules including a control module 305, a diagnostic module 310, a data storage module 315, a voltage sensing module 320, a speed setting module 325, a power conditioning module 330, a timeout module 335, a control/power bus module 340, a programming module 345, a service tool interface module 350, an expansion bus module 355, a harmonic emission reduction module 360, a visual feedback/interface module 365, a frequency detection module 370 and a current monitoring module 375.

It should be appreciated that according to various embodiments of the invention, each of the above-identified modules may be configured as a software application executing on computer hardware, an application specific integrated circuit (ASIC), firmware executing on a microprocessor of a PCB control unit, a combination of hardware and software, or other suitable configuration. In a preferred embodiment, each module will be a routine implemented in firmware and executed on a microprocessor of a PCB. Moreover, modules may be combined or broken into multiple additional modules, as desired. For example, the control module 305 may be one or more microprocessors, may be a digital signal processor (DSP) chip, an embedded processor and/or part of an embedded operating system (OS). Fewer or more modules may be used, and different modules than those illustrated in the Figure may be used as well.

In at least one embodiment, the diagnostic module 310 will perform one or more diagnostic functions relating to the operation of a vacuum cleaner control unit. For example, in at least one embodiment, the diagnostic module may monitor the operation of the motor through a sensor or other interface to determine if a locked rotor condition has occurred. If the rotor becomes locked, damage to the windings of the electric motor can occur. Thus, in this embodiment, if the controller detects a locked rotor condition, the diagnostic module 310 will cause the power conditioning module 330 to issue an instruction to the power conditioning module 330 to cut off power to the vacuum motor for a predetermined time period—for example, for 15 seconds. No power will be supplied during this time period, thereby making it impossible for a user to turn the vacuum motor back on. At the end of the 15 seconds, the user may then manually restart the vacuum motor. In at least one embodiment, the diagnostic module 310 may also cause the visual feedback module 365 to activate a visual indicator, such as a warning or error indicating LED to provide visual notification to the user of the temporary error condition—either by specifically identifying the condition or by generally indicating that a fault is detected.

In at least one embodiment the diagnostic module 310 may also perform a thermal shutdown function. In this embodiment, the diagnostic module 310 may be connected to a thermocouple or thermometer measuring the ambient temperature in the power unit. In a preferred embodiment, part of the flyback transformer circuit that supplies power to the control unit 300 includes an integrated thermal shut down function that is based on the current die temperature. When the flyback transformer shuts off power to the control unit 300, the control unit 300, including the power conditioning module 330, can no longer cause current to be delivered to the vacuum motor. Thus, the system is effectively shut off. In some embodiments this may comprise the flyback transformer may remain off until a predetermined time period has expired. In other embodiments, this the flyback transformer may remain off until the overheat condition is no longer detected, or until the temperature drops below another predetermined threshold. In embodiments in which a separate temperature sensing device is used, shutoff may also occur for a fixed time period, or until the temperature in the power unit has dropped below an acceptable threshold.

Still another function performed by the diagnostic module 310 in at least one embodiment of the invention is remote error condition reset. If an error condition occurs during operation of a central vacuum system, it is likely that the user is located away from the power unit. Therefore, via a control/power bus connection to each wall connector 130, the diagnostic module 310 may permit the operator restart operation by selecting a control on the wall unit or on the cleaning nozzle, without having to travel to the location of the power unit. In a preferred embodiment, the nozzle handle includes a fault indicator light or display to inform the operator of the fault condition and a reset switch that interfaces with the control unit 300 via the control/power bus module 340 connection at the wall connector 130. Alternatively, the wall connector itself 130 may include a reset switch to accomplish this, and may also include a fault indicator light or display.

Yet an additional function performed by the diagnostic module 310 is sensor monitoring. The control unit 300 may be connected to a variety of different sensors in the power unit 100 interfaced via the diagnostic module 310. For example, a sensor may notify the diagnostic module 310 that the dirt reservoir 115 is either detached from or insecurely attached to the power unit 100. The diagnostic module 310 may cause the visual feedback module 365 to display a message or activate an indicator to alert a user of this condition.

Another sensor may notify that the diagnostic module 310 that the filter 150 is either absent or loosely attached to the power unit 100. In various embodiments, this may be facilitated through vacuum pressure sensors that detect a pressure differential across the filter. A lack of differential or small differential may indicate that no filter is present or that it is improperly mounted. The occurrence of this condition may also cause the diagnostic module 310 to display a message, activate an indicator to alert a user as to the existence of this condition, or disable operation. Alternatively, a physical switch that is engaged with the filter when it is fully attached may be used to detect the presence of a filter.

Still another sensor may notify the diagnostic module 310 of variances in the pressure differential across the filter, which may indicate that the filter 150 needs to be cleaned or changed, that an obstruction such as a rag, plastic bag or other piece of debris is overly restricting air flow through the filter 150 or that the filter 150 is missing. As noted above, in addition to indicating when no filter is present, pressure differential sensors can also detect when the filter is clogged or blocked as indicated by a large pressure differential across the filter. Detection of a large pressure differential may also cause the diagnostic module 310 to display a message or activate an indicator to alert a user as to the existence of this condition, such as, a “Check Filter” message and/or indicator, and/or disable the device.

As noted above, in at least one embodiment, the diagnostic module 310 will shut off power to the vacuum motor and other electrical circuits upon the detection of certain error conditions. In at least one embodiment, the diagnostic module will impose a minimum shut off time, such as, for example, 15-30 seconds. By imposing a minimum shut off time, the diagnostic module will prevent the operator from damaging the system during a rotor jam by thermal runaway—a condition that occurs when over current causes the motor to rapidly overheat faster than the thermal sensor can monitor the temperature.

In at least one embodiment according to this invention, the control unit 300 also comprises a data storage module 315. The data storage module 315 stores data regarding the vacuum system's performance, such as time usage data and data obtained by the various other modules including line voltage levels, current levels, error condition occurrences, etc. The data storage module 315 preferably comprises a non-volatile memory structure such as flash memory, NAND memory or other non-volatile semiconductor memory, or alternatively, a magnetic storage device such as a hard drive.

In at least one embodiment of the invention, the control unit 300 also performs voltage sensing of the line voltage supplied to the power unit's conditioning module. In this embodiment, a voltage sensing module 320 measures the voltage across a flyback transformer while the secondary portion of the transformer is de-energized. Because the control unit 300 is already connected to the flyback transformer to receive its own power, sensing the voltage can be implemented without requiring additional components and prior to delivering power to the vacuum motor. In one sense, voltage sensing is done as a precaution to monitor the line voltage conditions. If dangerously high spikes in the line voltage are detected, the voltage sensing module 320 will cause the control module to instruct the power conditioning module 330 to shut off power to the vacuum motor to prevent damage to the motor 170 or the control unit 300. The voltage sensing module 320 may also record detected voltage levels, either periodically, or above or below predetermined thresholds, in the data storage module 315 so that a technician who later accesses the data in the data storage module 315 can be alerted as to the line voltage conditions under which the vacuum system has been operated.

Another feature provided by the voltage sensing module 320 of the control unit 300 is the ability to detect the type of line voltage and frequency to which the power unit is connected—typically 120 V or 240V. This enables a single PCB-based control unit to be used in heavy duty, high voltage models and regular duty lower voltage models, thereby eliminating the excess manufacturing costs of having to produce separate control units for each. This also allows a single motor to be used in international products, where the supply voltage may be different from the United States.

Similarly, the control unit 300 also may include an AC line frequency detection module 370. Different countries and regions around the world utilize different AC line frequencies. For example, some countries' power systems are based on 60 Hz and others on 50 Hz alternating current power. As a result, manufacturers must make different systems intended for different geographic markets. The programmable PCB-based control unit 300 according to one embodiment of the present invention detects the local AC line frequency and makes any necessary adjustments to the control program. This detection may also be performed through the flyback transformer interface.

In at least one embodiment of the invention, the control unit 300 also comprises a speed setting module 325. The speed setting module 325 receives a user input selection from either the user interface control/power bus module 340 connected nozzle or the visual feedback/interface module 365 on the power unit itself. As will be discussed in greater detail in the context of the programming module 345, the speed setting module 325 may comprise a plurality of different speed setting programs. Once a particular program has been programmed into the control unit 300 via the programming module 345, the speed setting module 325 will allow the vacuum motor 170 to be operated at any of the selected speeds available in the current program. In a preferred embodiment, once a user selects a speed setting via the control/power bus module 340, the control unit causes the power conditioning module 330 to perform phase control via that TRIAC—that is, pulsing current to the vacuum motor a predetermined frequency.

Another feature of the control unit 300 according to at least one embodiment of the invention is a timeout module 330. Instead of using a separate circuit or timer to keep track of current continuous operating time, the timeout module 330 utilizes the existing functionality of the microprocessor based control unit 300 to track time. In at least one embodiment, this may be implemented by monitoring zero line crossings of the line voltage once the vacuum motor is engaged—each 120 or 100 crossing is equivalent to one second in 60 Hz and 50 Hz systems respectively. Alternatively, timeout may facilitated through a system clock or other timing device. When the time equals or exceeds a preprogrammed threshold, such as 30 minutes, the timeout module 335 will cause the power conditioning module 330 to cut off power to the vacuum motor 170. In various embodiments, the user may be able to override the cutoff by manually restarting the vacuum motor 170 with a switch. In various other embodiments, the timeout module 335 prevents the system from being restarted for a predetermined period of time, such as 10 minutes, to allow the motor, control unit and other internal circuits and system components to cool off. If desired, the user may also be able to select the timeout time setting with the interface 160.

Yet another feature of the control unit 300 according to various embodiments of the invention is a control/power bus module 340. In a preferred embodiment, the control/power bus module 340 supplies low voltage power to the nozzle via the wall connector to power a switch on the nozzle that activates the power unit. In such embodiments, power for indicators, interfaces and motor-driven components of either the connector 130 or nozzle 200 is supplied via a standard wall connector in the residential structure via a separate power supply cord integral to the nozzle. In addition to a physical interface to the nozzle, the control/power bus module 340 may also comprise a wireless interface. In such embodiments, the nozzle functions as a wireless remote control for passing control signals to the power unit and to receive signals such as status indicators and other messages. In various embodiments this may be performed using a standard wireless protocol such as ZigBee, R F, IrdA, 802.11x, etc. The control/power bus module 340 may also supply one or more two-way communication lines between the user end (i.e., wall connector 130 or nozzle 200) and the power unit end for issuing commands to the power unit 100 and for sending status and other signals to the user end. User end-generated commands to turn on the vacuum systems are received by the control/power bus module 340. In turn, based on the user command, the control/power bus module 340 causes the power conditioning module 330 to deliver power to the vacuum motor 170 and to the wall connector 130 through the power cable 142 of the control/power bus module 340.

Another novel feature of the control unit 300 according to one or more embodiments of the invention is its programmability. The programming module 345 permits the control unit 300 to be programmed with an appropriate control program after the power unit 100 is manufactured but before it is shipped to the consumer. This feature increases the flexibility to manufacturers and eliminates the costs of manufacturing separate control units for each product in a manufacturers' product line. The control unit 300 may also be set up to be programmable even after it is delivered to the customer or installed in a home, which can be useful for service and to add features or upgrade the device's performance. The programming module 345 permits program information to be written to the control unit 345, where, in at least one embodiment, it is stored in a memory structure. The transfer can be through any known means, such as a physical connector, a standard serial, parallel, USB or IEEE1394 connector, a proprietary, non-standardized connector, a wireless link such as IrDA, 802.11x, BlueTooth, UWB, ZigBee (802.15.4), or other wireless communication link, and so on. In various embodiments, the program information is stored as firmware in flash memory, or other non-volatile electronic data structure. In various other embodiments, the program information is stored in the data storage module 315.

In at least one embodiment, the manufacturer may not know the particular model of vacuum cleaning system that the control unit 300 will be installed in at the time the control unit 300 is manufactured. Thus, the control unit 300 can be made without being tied to a particular model. After the manufacturer determines the particular product, including motor and feature set, the programming module 345 is used to “upload” the designated control program from a computer or programming tool that interfaces with the control unit 300 via the programming module's communication interface.

In at least one other embodiment, the programming module 345 may be used to specify additional late-stage product information. For example, in certain segments of the vacuum market, a manufacturer may desire to sell two or more vacuums with the same vacuum motor but at different price points. Thus, although the vacuums are capable of outputting the same level of air watts, 600 air-watts for example, one is sold as being lower power. In various embodiments, this is facilitated by programming the control unit 300 with different performance levels. That is, the high powered model is programmed with a control program specifying a performance level that allows the vacuum motor to be turned up fully to 600 air watts, while the other model is programmed with a control program specifying a performance level that allows the vacuum to be turned up to only 450 air watts. The programmable performance levels facilitated by the programming module 345 permit a manufacturer to create market differentiated products using only a single vacuum motor. This reduces manufacturing costs because fewer motor types are utilized without reducing the breadth of the product line. For a large, multinational product line, this can reduce the number of required motors from dozens to just a few, or even one.

Still another feature of the control unit 300 according to the various embodiments of the invention is a service tool interface module 350. The service tool interface module 350 provides an interface for a diagnostic/service tool of a repair person to electronically communicate with the control unit 300 of the power unit 100 of the vacuum system, and to access the performance information recorded by the control unit 300 in the data storage module 315. In at least one embodiment, the service tool interface module 350 includes a physical connector on the power unit that is mated with a reciprocal connector attached to or integral with a service tool device. In at least one other embodiment, the service tool interface module 350 includes a wireless transceiver based on IrDA, 802.11x, BlueTooth, ZigBee (802.15.4) or other suitable standard-based or proprietary wireless communication protocol that can be used to facilitate two-way communication between the power unit and the service tool. In still an additional embodiment, the service tool interface module may include a modem that is connected to a standard RJ-11 residential telephone connector. In this embodiment, the service tool interface module 350 may periodically send information to a service tool data server over a residential telephone line. Alternatively, a technician may be able to “call” into the power unit via the modem and facilitate transfer of performance information and automated analysis of this information. Also, the service interface tool module 350 and the programming module 345 may be utilized to perform control program updates, diagnostics, upgrades, expansions, and so on.

Another feature of the control unit 300 according to the various embodiments of the invention is an expansion control bus 355. In at least one embodiment, the expansion bus module 355 is a electrical pin, cartridge or plug-type bus connector that can be used to add additional user interface and accessory features. In at least one embodiment, the expansion bus module 355 is used to connect the user interface 160 or another user interface device to the control unit 300, thereby enabling bidirectional communication between the control unit 300 and user interface 160 and also enabling output of status and other information to the user via the interface 160.

An additional novel feature provided by control unit according to one or more embodiments of the present invention is harmonic emission reduction. The harmonic emissions reduction module 360 insures that the power conditioning module performs power factor correction according to the relevant standards. Harmonic emissions reduction shapes the input current of off-line power supplies to maximize the real power available from the power supply. Ideally, from the perspective of the line power, the vacuum cleaning system should present a load that emulates a pure resistor, in which case the reactive power drawn by the device is zero. Inherent in this scenario is the freedom from input current harmonics. The current is a perfect replica of the input voltage (usually a sine wave) and is exactly in phase with it. In this case the current drawn from the supply is at a minimum for the real power required to perform the needed work, and this minimizes losses and costs associated not only with the distribution of the power, but also with the generation of the power and the capital equipment involved in the process. The freedom from harmonics also minimizes interference with other devices being powered from the same source.

Another reason for employing harmonic emissions reduction (also known as “power factor correction”) in electrical consumer products is to comply with regulatory requirements. Currently, electrical equipment in Europe must comply with the European Norm EN61000-3-2, which requires that the current harmonics of all line-connected equipment stay below prescribed limits. This requirement applies to most electrical appliances with input power of 75 W or greater, and it specifies the maximum amplitude of line frequency harmonics up to and including the 39^(th) harmonic. While this requirement is not yet in place in the United States, equipment manufacturers attempting to sell products worldwide are designing for compliance with this requirement.

In various embodiments, performing harmonic emissions reduction may comprise performing a method similar to that disclosed in U.S. patent application Ser. No. 11/243,918, which is hereby incorporated by reference in its entirety into the disclosure of this application.

In various embodiments, when the control unit 300 is programmed with the control program using the programming module 345, a data field or bit may be used to designate whether or not to activate the harmonic emissions reduction module 360.

In addition to the optional user interface 160 connectable to the expansion bus module 355, the control unit 300 according to one or more embodiments of the invention comprises a visual feedback module 365 adapted to provide status, error and other messages to the user. In one embodiment, the visual feedback module 365 displays messages on an LED panel or display screen located on an outer surface of the power unit of the vacuum cleaning system. Alternatively, or in addition, the visual feedback module 365 may cause the control/power bus module 340 to send a signal to each wall connector 130 and or vacuum nozzle 200 to illuminate a status indicator or display a message on an integral display screen regarding a current status of the vacuum system. For example, a green LED may be illuminated on the wall connector when the vacuum is ready for use. A red LED may be illuminated if an error has occurred. Also, a yellow LED may be illuminated if a condition exists that requires the user to check the power unit, such as, for example, if the dirt collection unit is full or has not be securely attached to the main body of the power unit.

Yet another feature of the control unit 300 according to at least one embodiment of the invention is a current monitoring module 375. The current monitoring module 375 comprises a current measuring device supplying current reading measurements to the control unit 300. If an overcurrent condition is detected, such as may occur in a rotor jam, transformer failure or other breakdown, the current monitoring module 375 causes the power conditioning module 330 to shut off power to the vacuum motor 170 for a predetermined period of time. The current monitoring module 375 may also cause the visual feedback module 365 to display an error message or illuminate an error status indicator to inform a user of the occurrence of the error condition. The current monitoring module 375 may also record detected current conditions in the data storage module 315 so that if an overcurrent condition occurs, a service technician will be made aware of this when viewing the historical performance data in the data storage module 315.

Referring now to FIG. 5, an exemplary circuit diagram illustrating a circuit topology for the vacuum cleaning system control unit according to at least embodiment of the invention is provided. The circuit diagram illustrates a single microprocessor-based PCB controller 400. Power is supplied by AC line voltage via IEC320 connector 405. Low voltage DC power for the circuit 400 is provided by the universal power supply. The power supply feeds the transformer 415. The IEC320 connector 405 is a modular AC socket that is an international standard, and allows different cord sets to be used with the same product. This DC power is used by the microprocessor 410 and other digital components. The microprocessor may be any suitable embedded processor containing a programmable flash memory module. The control circuit's control program is written via the programming connector 435. In the exemplary embodiment of FIG. 5 this is a pin connector. However, as noted herein, a wireless transceiver may be utilized to facilitate control program upload. Optocoupler 425 receives digital control signals from the microprocessor 410, and in response sends low current signals to the TRIAC 430 that dictate the phase control performed by the TRIAC. The TRIAC is also connected the AC line power (L). Based on a current level received from the optocoupler 425, it controls the percentage of line current that flows through the TRIAC to the vacuum motor. Low-voltage connection to the wall connectors is provided via a low voltage connector 420. Connector 440 provides an expansion connector interface.

It should be appreciated that the various circuit elements illustrated in the control unit circuit 400 of FIG. 5 are exemplary only. More or fewer elements may be utilized as well as completely different elements than those shown in the Figure, without departing from the spirit or scope of the invention.

The embodiments of the present inventions are not to be limited in scope by the specific embodiments described herein. For example, although many of the embodiments disclosed herein have been described in the context of a programmable, PCB-based control unit for a central vacuum cleaning system, other embodiments, in addition to those described herein, will be apparent to those of ordinary skill in the art from the foregoing description and accompanying drawings. Thus, such modifications are intended to fall within the scope of the following appended claims. Further, although some of the embodiments of the present invention have been described herein in the context of a particular implementation in a particular environment for a particular purpose, those of ordinary skill in the art will recognize that its usefulness is not limited thereto and that the embodiments of the present inventions can be beneficially implemented in any number of environments for any number of purposes. For example, as the control unit or other features described herein can be used with integrated vacuums, such as canister vacuums and upright vacuums, in addition to the being useful with the illustrated central vacuum. Many modifications to the embodiments described above can be made without departing from the spirit and scope of the invention. Accordingly, the claims set forth below should be construed in view of the full breath and spirit of the embodiments of the present inventions as disclosed herein. Also, while the foregoing description includes many details and specificities, it is to be understood that these have been included for purposes of explanation only, and are not to be interpreted as limitations of the present invention. 

1. A vacuum cleaner system comprising: a line power input; a dirt collection unit; at least one dirty air intake conduit defining an airflow path to the vacuum unit and terminating in a dirt collection unit; a vacuum motor adapted to generate a working airflow from the dirty air intake to conduit to the dirt collection unit; and a programmable control unit having a power conditioning module and adapted to be programmed with one or more of a plurality of different control programs that control the power conditioning module to provide power from the line power input to drive the vacuum motor.
 2. The vacuum cleaner system according to claim 1, wherein the programmable control unit comprises a microprocessor-based printed circuit board (PCB).
 3. The vacuum cleaner system according to claim 1, wherein the power conditioning module is controlled by the programmable control unit to deliver power to the vacuum motor.
 4. The vacuum cleaner system according to claim 1, wherein the dirt collection unit, at least one dirty air intake, vacuum motor, and programmable control unit are located in a power unit of a central vacuum system.
 5. The vacuum cleaner system according to claim 1, wherein one of the plurality of different control programs is stored in memory structure in the control unit.
 6. The vacuum cleaner according to claim 1, wherein each of the plurality of different control programs is correlated to a particular feature set.
 7. The vacuum cleaner system according to claim 6, wherein each feature set comprises at least a maximum air watt output level for the vacuum motor.
 8. The vacuum cleaner system according to claim 1, wherein the control unit is adapted to detect a voltage level of the line power input.
 9. The vacuum cleaner system according to claim 6, wherein detecting a voltage level comprises measuring the voltage across a fly back transformer supplying power to the control unit.
 10. The vacuum cleaner system according to claim 1, wherein the control unit further comprises an expansion interface.
 11. The vacuum cleaner system according to claim 10, wherein the expansion interface comprises an electrical connector adapted to interface with at least one expansion boards utilizing a reciprocal connector interface.
 12. The vacuum cleaner system according to claim 1, wherein the control unit comprises a memory structure and the control unit is adapted to record operational data relating to operation of the vacuum system in the memory structure.
 13. The vacuum cleaner system according to claim 12, wherein operational data consists of information selected from the group consisting of measured motor current levels, line voltage levels, faults, motor operation hours, on/off cycles, filter changes and combinations thereof.
 14. The vacuum cleaner system according to claim 1, wherein the control unit further comprises a service tool interface.
 15. The vacuum cleaner system according to claim 14, wherein the service tool interface comprises an interface selected from the group consisting of a connector, a wireless interface and combinations thereof.
 16. The vacuum cleaner system according to claim 1, further comprising a user interface in electrical communication with the control unit and adapted to receive user inputs and output status information.
 17. The vacuum cleaner system according to claim 16, wherein the user interface comprises an indicator panel with one or more status indicators.
 18. The vacuum cleaner system according to claim 1, wherein the control unit is further adapted to execute a power shut off if at least one error condition is detected from the group consisting of a detected locked motor rotor, a detected line voltage exceeding a predetermined threshold, a detected current level exceeding a predetermined threshold, a detected temperature exceeding a predetermined threshold, a period of continuous vacuum motor operation exceeding a predetermined threshold, filter missing, filter not completely attached, dirt collection reservoir missing, dirt collection reservoir not complete attached, and combinations thereof.
 19. The vacuum cleaner system according to claim 18, further comprising a remote user interface in electrical communication with the control unit and adapted to permit a user of the system to restart the vacuum system after a power shut off event.
 20. The vacuum cleaner system according to claim 1, wherein the control unit is adapted to perform harmonic emissions reduction.
 21. The vacuum cleaner system according to claim 20, wherein performing harmonic emissions reduction comprises reducing harmonic emissions in compliance with European Norm EN61000-3-2.
 22. The vacuum cleaner system according to claim 1, wherein the control unit is further adapted to detect an AC line frequency connected to the vacuum system and to control the power conditioning module based on the detected frequency.
 23. The vacuum cleaner system according to claim 1, wherein the programmable control unit is adapted to be programmed with a serial number of a vacuum cleaner during vacuum cleaner system assembly.
 24. A product line of distinct central vacuums, each central vacuum in the product line comprising: an integral power unit, comprising: a line power input; a dirty air intake; a dirt reservoir; a particulate barrier; an air outlet; a vacuum motor configured on a side of the particulate barrier fluidly opposite the dirt reservoir and adapted to generate a working airflow from the dirty air intake to the particulate barrier, and expect the working airflow out of the air outlet; and a programmable control unit, including a power conditioning unit adapted to condition a line power, wherein the programmable control unit is programmed with a control program specific to one of the distinct central vacuums for controlling the power conditioning unit, wherein the control program comprises a feature set including a maximum power watt output level for the vacuum motor.
 25. A vacuum cleaner system comprising: a line power input; an air intake; a dirt collection reservoir; a vacuum motor adapted to generate a working airflow from the dirty air intake to conduit to the dirt collection unit; and a programmable control unit including a power conditioning module and adapted to be programmed with one or more of a plurality of different control programs, wherein each control program corresponds to a different product in a vacuum manufacturer's product line and specifies a maximum current level for the power conditioning module to deliver to the vacuum motor thereby providing each different product in the product line with at least one different operational characteristic. 